Surfaces that exhibit dry-erase properties can be written on with marker pens, such as, but not limited to, dry-erase marker pens, and wiped clean with a dry cloth, a dry paper towel, a dry tissue, or a dry eraser, for example. Dry-erase surfaces may be used in, for example, classrooms, corporate offices, and homes.
Coating formulations have been proposed that provide a surface that is resistant to graffiti, such as might be produced from a marker pen, such as, but not limited to, dry-erase marker pens. As such, these formulations provide a surface that exhibits dry-erase properties. Some of these formulations are two-component waterborne compositions in which one component comprises a polyacrylate polyol and another component comprises an isocyanate-functional cross-linker. While these formulations may result in a cured polyurethane coating that exhibits graffiti-resistant/dry-erase properties, the isocyanate-functional cross-linkers can have perceived health, safety, and/or environmental concerns associated with them. As a result, these formulations are not typically suitable for use in do-it-yourself (“DIY”) applications since they should be applied by skilled and well-trained paint applicators that are familiar with handling such materials in the proper manner. In addition, exposure to the area in which the coating has been applied often must be prevented for an extended period of time, until all the isocyanate-functional materials have been completely reacted. Polyaziridine cross-linkers also have an unfavorable toxicity profile that renders them undesirable for use in DIY applications.
Other coating formulations that have been proposed to provide a surface exhibiting graffiti-resistant/dry-erase properties may require special curing equipment to cure the coating at elevated temperature and/or with actinic radiation. Still other coating formulations may require specialized fluoro- and/or silicon-based materials.
In addition to producing an initially dry-erasable surface, it is desirable that a coating composition produce a cured coating that provides a dry-erasable surface after long term exposure to a dry-erase marking. That is, the coated surface should be dry-erasable even when a marking from a marker pen, such as a dry-erase marker pen, is left on the surface for a long period of time, such as up to 5 days.
In addition, often for environmental reasons, waterborne coating compositions are sometimes preferred over organic solvent-borne compositions.
As a result, it would be desirable to provide improved waterborne coating compositions that can be cured at ambient conditions and which are suitable for use in DIY applications to provide a surface that exhibits both initial and long-term graffiti-resistant/dry-erase properties. The present invention was made in view of the foregoing.